钢纤维的端钩数目对钢纤维混凝土性能的影响

Effect of Number of End Hooks of Steel Fibers on Performance of Steel Fiber Reinforced Concrete

摘要:

通过拉拔试验、抗压强度试验和切口梁弯拉性能试验，研究了钢纤维的端钩数目对钢纤维混凝土（SFRC）性能的影响规律及机理。结果表明，钢纤维的端钩数目越多，钢纤维与混凝土基体的极限黏结强度越高；钢纤维的端钩数目对SFRC的抗压性能影响不大，但端钩数目为1的钢纤维对SFRC的抗压强度有一定提升作用；随着钢纤维端钩数目的增加，SFRC 弯拉曲线下降段的下降幅度减小，曲线趋于饱满，且试件所能承受的弯拉应力增大；随着裂缝的不断扩展，端钩数目为2和3的钢纤维可以使SFRC试件在发生断裂且产生较大形变后依然维持较高的残余弯拉强度。

Abstract:

The effect of the number of steel fiber end hooks on the performance of steel fiber reinforced concrete （SFRC） and its mechanism were studied through single wire pull-out test， compressive strength test， and notched beam bending-tensile performance test. The results show that as the number of end hooks on the steel fiber increases， the ultimate bond strength between the steel fiber and the concrete matrix also increases. The number of end hooks has little effect on the compressive performance of SFRC， although steel fibers with a single end hook can slightly enhance the compressive strength. With more end hooks， the descending branch of the SFRC flexural-tensile curve becomes less steep， the curve becomes fuller， and the specimens can sustain higher flexural-tensile stresses. As cracks continue to propagate， steel fibers with two or three end hooks enable SFRC specimens to maintain relatively high residual flexural-tensile strength even after fracture and large deformation occur.